#ifdef _WIN32
#include <errno.h>
#include <io.h>
#include "h/mman.h"
#include "h/windows.h"
#ifndef FILE_MAP_EXECUTE
#define FILE_MAP_EXECUTE    0x0020
#endif /* FILE_MAP_EXECUTE */

static int __map_mman_error(const DWORD err, const int deferr) {
  if (err == 0)
    return 0;
//TODO: implement
  return err;
}
static DWORD __map_mmap_prot_page(const int prot) {
  DWORD protect = 0;
  if (prot == PROT_NONE)
    return protect;
  if ((prot & PROT_EXEC) != 0) {
    protect = ((prot & PROT_WRITE) != 0) ?
      PAGE_EXECUTE_READWRITE : PAGE_EXECUTE_READ;
  } else {
    protect = ((prot & PROT_WRITE) != 0) ?
      PAGE_READWRITE : PAGE_READONLY;
  }
  return protect;
}
static DWORD __map_mmap_prot_file(const int prot) {
  DWORD desiredAccess = 0;
  if (prot == PROT_NONE)
    return desiredAccess;
  if ((prot & PROT_READ) != 0)
    desiredAccess |= FILE_MAP_READ;
  if ((prot & PROT_WRITE) != 0)
    desiredAccess |= FILE_MAP_WRITE;
  if ((prot & PROT_EXEC) != 0)
    desiredAccess |= FILE_MAP_EXECUTE;
  return desiredAccess;
}
void* mmap(void* addr, size_t len, int prot, int flags, int fildes, OffsetType off) {
  HANDLE fm, h;
  void* map = MAP_FAILED;
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable: 4293)
#endif
  const DWORD dwFileOffsetLow = (sizeof(OffsetType) <= sizeof(DWORD)) ?
    (DWORD)off : (DWORD)(off & 0xFFFFFFFFL);
  const DWORD dwFileOffsetHigh = (sizeof(OffsetType) <= sizeof(DWORD)) ?
    (DWORD)0 : (DWORD)((off >> 32) & 0xFFFFFFFFL);
  const DWORD protect = __map_mmap_prot_page(prot);
  const DWORD desiredAccess = __map_mmap_prot_file(prot);
  const OffsetType maxSize = off + (OffsetType)len;
  const DWORD dwMaxSizeLow = (sizeof(OffsetType) <= sizeof(DWORD)) ?
    (DWORD)maxSize : (DWORD)(maxSize & 0xFFFFFFFFL);
  const DWORD dwMaxSizeHigh = (sizeof(OffsetType) <= sizeof(DWORD)) ?
    (DWORD)0 : (DWORD)((maxSize >> 32) & 0xFFFFFFFFL);
#ifdef _MSC_VER
#pragma warning(pop)
#endif
  errno = 0;
  if (len == 0
      /* Usupported protection combinations */
    || prot == PROT_EXEC) {
    errno = EINVAL;
    return MAP_FAILED;
  }
  h = ((flags & MAP_ANONYMOUS) == 0) ?
    (HANDLE)_get_osfhandle(fildes) : INVALID_HANDLE_VALUE;
  if ((flags & MAP_ANONYMOUS) == 0 && h == INVALID_HANDLE_VALUE) {
    errno = EBADF;
    return MAP_FAILED;
  }
  fm = CreateFileMapping(h, NULL, protect, dwMaxSizeHigh, dwMaxSizeLow, NULL);
  if (fm == NULL) {
    errno = __map_mman_error(GetLastError(), EPERM);
    return MAP_FAILED;
  }
  if ((flags & MAP_FIXED) == 0) {
    map = MapViewOfFile(fm, desiredAccess, dwFileOffsetHigh, dwFileOffsetLow, len);
  } else {
    map = MapViewOfFileEx(fm, desiredAccess, dwFileOffsetHigh, dwFileOffsetLow, len, addr);
  }
  CloseHandle(fm);
  if (map == NULL) {
    errno = __map_mman_error(GetLastError(), EPERM);
    return MAP_FAILED;
  }
  return map;
}
int munmap(void* addr, size_t len) {
  if (UnmapViewOfFile(addr))
    return 0;
  errno = __map_mman_error(GetLastError(), EPERM);
  return -1;
}
int _mprotect(void* addr, size_t len, int prot) {
  DWORD newProtect = __map_mmap_prot_page(prot);
  DWORD oldProtect = 0;
  if (VirtualProtect(addr, len, newProtect, &oldProtect))
    return 0;
  errno = __map_mman_error(GetLastError(), EPERM);
  return -1;
}
int msync(void* addr, size_t len, int flags) {
  if (FlushViewOfFile(addr, len))
    return 0;
  errno = __map_mman_error(GetLastError(), EPERM);
  return -1;
}
int mlock(const void* addr, size_t len) {
  if (VirtualLock((LPVOID)addr, len))
    return 0;
  errno = __map_mman_error(GetLastError(), EPERM);
  return -1;
}
int munlock(const void* addr, size_t len) {
  if (VirtualUnlock((LPVOID)addr, len))
    return 0;
  errno = __map_mman_error(GetLastError(), EPERM);
  return -1;
}
#endif